NEW ACCOUNTING PRONOUNCEMENTS (Details) (Maximum)	9 Months Ended
Sep. 30, 2012
Maximum
Percentage likelihood of fair value of a reporting unit being less than its carrying value	50.00%

Represents the percentage likelihood that the fair value of a reporting unit is less than its carrying amount.

No definition available.

Name:	ggc_PercentageLikelihoodThatFairValueOfReportingUnitIsLessThanItsCarryingAmount
Namespace Prefix:	ggc_
Data Type:	num:percentItemType
Balance Type:	na
Period Type:	duration